1. Field of the Invention
This invention relates to a new class of novel ceramic materials that are formed from linear inorganic-organic hybrid polymers of varying molecular weight. These new ceramics are formed from oxidatively stable thermosetting polymers which, in turn, are formed from linear polymeric materials having repeating units that contain at least one alkynyl group for cross-linking purposes and at least one bis(silyl or siloxanyl)carboranyl group. The thermosetting polymers are converted into the novel ceramics, the subject of the present invention, at elevated temperatures.
2. Description of the Related Art
The cross linking of acetylenic polymers has been demonstrated by Neenan et al. in Hypercross-Linked Organic Solids: Preparation from Poly(aromatic diacetylenes) and Preliminary Measurements of Their Young's Modulus, Hardness, and Thermal Stability published in 21 MACROMOLECULES 3525-28 (1988). The reaction for cross linking acetylenic polymers illustrated by Neenan et al. is as follows: ##STR1## where n is a positive integer. Other similar cross linking reactions are demonstrated by Callstrom et al. in Poly[ethynlyene(3-n-butyl-2,5-thiophenediyl)-ethynylene]: A Soluble Polymer Containing Diacetylene Units and Its Conversion to a Highly Cross-Linked Organic Solid published in 21 MACROMOLOCULES 3528-30 (1988). For example, see the reactions shown below taken from Callstrom et al.: ##STR2##
There is a need for oxidatively stable ceramics at elevated temperatures that have properties for making rigid components therefrom, such as engine parts, ceramic tiles, oxidatively stable coatings, and composite products for structural applications.